We are considering purchasing a home with cast iron plumbing lines - please advise as to hazards and fixes to remedy this outdated plumbing; also costs.

I cut it with my sawsall (reciprocating saw) and a metal/wood combination blade. I use a rubber flex fitting to take it from the cast iron size down to the black ABS I am connecting it to. I have one job that has been in place for 10 years with no problems. The only thing with cast iron is that it is extremely heavy. Be careful when you cut it and let it fall. Have someone to ease it to the floor!
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I use a rubber flex fitting to take it from the cast iron size down to the black ABS I am connecting it to.

Those "rubber flex fittings" are designed specifically for joining buried horizontal runs of waste piping.

Using them indoors or for vertical connections is specifically forbidden by code in about 99.9% of the country.

We are considering purchasing a home with cast iron plumbing lines - please advise as to hazards and fixes to remedy this outdated plumbing; also costs.

If the cast iron piping is in good repair and you don't intend to immediately remodel the home, then I'd leave it alone.

Cast iron waste piping is in many ways far superior to modern plastic waste piping.

The only real minus to the plumbing system is it's age -- In '59 code still allowed 1-1/2" drains, traps and trap-arms for kitchen sinks, lavatories, clotheswashers, bathtubs and laundry tubs.

If you plan on upgrading the waste lines, replace the above mentioned 1-1/2" drains back to the 2" hubs in the larger cast iron stacks and re-run them in 2".

I agree with Growler. If it ain't broke don't fix it! I live in a 1954 home with cast iron drainage. No problems! Good luck in your new hoime.